Structural Determination of a Transcribing RNA Polymerase II Complex
Final rept. 1 May 1997-30 Apr 2000
STANFORD UNIV CA RYAN LAB
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The purpose of the proposed research was to provide a structural basis for understanding the mechanism of transcription, its regulation, and altered regulation as occurs in tumor cells. The goal of the proposed research is to determine the X-ray structure of RNA Polymerase II in the midst of transcribing RNA from a DNA template. Despite challenges involved in this project, a major achievement is at hand. Firstly, a mainchain model of RNA Polymerase II with distinct features directly involved in transcription has been achieved. Secondly, two biochemical systems allowing for the generation of elongation complexes and thirdly the collection of X-ray diffraction data sets of two different elongation complexes has been achieved. Structural data derived from molecular replacement with the mainchain model shows that in the elongation complex, a key domain moves relative to the mainchain model, and acts as a clamp for nucleic acids in the active site cleft. A refined model of polymerase will shortly be available for molecular replacement with the elongation diffraction data, which should allow for the completion of the main goal of this project.
- Medicine and Medical Research
- Polymer Chemistry